


The Laziest Brother

by Vexatious



Category: Undertale (Video Game)
Genre: Alternate Universe - Underswap, Ecto-Genitalia (Undertale), Ecto-Penis (Undertale), Ecto-Vagina (Undertale), Explicit Language, Explicit Sexual Content, Forced Masturbation, M/M, Multiple Orgasms, NOT Dubcon, Overstimulation, Papyrus is Lazy, Sex Toys, Swapcest - Freeform, Underswap Papyrus, Underswap Sans, lewdberry
Language: English
Status: Completed
Published: 2017-11-27
Updated: 2017-11-27
Packaged: 2019-02-07 11:50:11
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,921
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12840549
Author URL: https://archiveofourown.org/users/Vexatious/pseuds/Vexatious
Summary: How can Papyrus be so lazy?! Good thing the Magnificent Sans is here to help!





	The Laziest Brother

**Author's Note:**

> Based on: [18+ artwork](https://psicro.tumblr.com/post/165946952310/pappy-i-was-cleaning-under-the-sink-and-found-my)  
> Check out my Tumblr: [vex-bittys](http://vex-bittys.tumblr.com)

Sans huffed in frustration as he shoved honey-stained hoodies and what must surely have been  _every single sock_  in the Underground into the washing machine. He didn’t really care that Papyrus didn’t help with the chores; his lazy brother had no sense of acceptable cleanliness. It didn’t even bother him that the lanky skeleton came home from napping on the job to nap on the couch instead. No, the final straw for Sans was his brother’s complete disregard for his own… personal maintenance.

Sans made sure Papyrus had clean clothes and hearty meals, and he’d even gone through the trouble of creating a pocket pussy out of his own bright blue magic so that Papy could take care of his sexual needs as well. It wasn’t like he’d done it for selfish reasons or anything. The pleasure he experienced whenever Papy used the toy was just a welcome bonus, but lately his lazybones brother hadn’t. Been. Using. It.

Sans only felt concerned for Papyrus’ well-being (obviously!); The Dating Manual: Volume 2 clearly stated the necessity of sexual release to promote mental and physical health! How could Papy neglect something so important? His laziness knew no bounds! Sans grumbled as he scrubbed the kitchen floor.

Sans had to use a wooden stepstool to reach the sink, and as he rinsed the scrub brush, he lost his balance and slipped off of the stool and banged his head against the cupboard door. The door hadn’t been properly latched, and it swung open, revealing an under-the-sink treasure trove of Papy’s junk. With a sigh, Sans got to work clearing out the small storage space. He found more socks (!), an entire skeleton’s worth of discarded bone attacks, a bag of human kibble (just in case), and a glowing bright blue cylinder. Unbelievable!

Sans stomped into the living room, right up to the loudly snoring orange lump on the couch and jabbed a gloved finger into the ribcage of his snoozing brother. “Papyrus!”

The tall skeleton yelped and flopped onto the floor. “Wha?” Papyrus blinked sleepily.

“Papy I was cleaning under the sink and found my detachable toy. Why didn’t you tell me that you lost it?” Sans scolded, waving the sex toy in question in his brother’s face. Papyrus awakened fully as the sight of the pocket pussy sent waves of magic to pool in his pelvis.

Sans noticed the telltale orange glow of his brother’s arousal, not that Papyrus bothered trying to hide it. Lazy!

“It’s been weeks, Papyrus! You haven’t been practicing any of the techniques I taught you, have you?” Sans brushed his hand over the bulge in Papyrus’ khaki shorts, coaxing a breathy whimper from his brother. He could feel the erection straining against the fabric. Obviously, Papyrus had been neglecting himself, and Sans wouldn’t tolerate such self-deprivation!

“Gosh, you really do need my help, don’t you?” Sans rubbed the front of Papy’s shorts harder; a bubble of precum leaked through the fabric.

“Ah… uhm?” Sweat beaded Papyrus’ skull as he struggled to respond coherently.

“Those aren’t even words! This is what happens when you ignore your training exercises, Papy.” Sans deftly unfastened his brother’s pants. “I’m going to teach you a lesson about discipline, so we’re going to do all the training you missed  _right now_.”

“Hah,” gasped Papyrus. He loved it when brother took charge like this.

“You have to ask for it properly, brother.” Sans grinned wickedly, lightly trailing his leather-clad fingertips up the underside of Papy’s cock. When he got to the tip, he pressed down lightly on the slit with his thumb, milking more precum from the swollen member. Never breaking eye contact with his brother, Sans lifted his thumb to his mouth and licked it.

“Please,” he gasped, regretting the utter desperation in his tone brought on by over two weeks of not masturbating. He’d barely be able to last at this rate. Why didn’t Sans just give him the sex toy? The teasing was too much!

“Please what, Papy? You have to say it.” Normally Sans would reprimand him if he used foul language, but this lewd side of his brother was hard to resist.

”Please let me fuck your pussy,” he begged in a rush as Sans’ hand encircled his cock and squeezed. “Please take my fat cock in your tight little cunt!” If Sans didn’t hurry up and give him the toy, he’d be cleaning cum out of the carpet.

“No,” said Sans, and Papyrus thought he might dust from unfulfilled desire. Sans wasn’t done talking though. “Because  _I’m_  going to do it.”

Papyrus didn’t even have time to process the statement before Sans lowered the slick entrance of the toy onto his aching shaft. Sans moved so slowly, guiding his cock in inch by inch even though the magical toy could easily take his ample girth much faster. Papyrus reached out a hand to help speed things along, but Sans slapped it away gently.

“No, Papyrus. You had your chance. Now we’re going to do it my way.” Sans tried to keep his voice even; he prided himself on his immaculate control. He refused to yield to the pleasure of his brother’s thick cock filling him. He had to focus on teaching Papyrus a lesson!

Even though the magical device was detached from his body, Sans could feel the way his walls clenched around his brother’s length, gripping it so tightly. Papyrus’ orange magic showed through the translucent toy in an ethereal and very intimate way that had them both blushing hotly. With the fullness of Papy’s cock hilted within him, he started to flex the muscles of his pelvic floor- his brother’s greatest weakness. Alphys always said not to underestimate the importance of strategy!

Papyrus dug his phalanges into the thick shag carpet. Letting Sans take charge turned out to be the best idea ever. Only the Magnificent Sans could stroke his cock like that without even having to move. Stars, the lust and euphoria overwhelmed him.

“Sans… Sans wait… I’m… I’m so close… Slow down…!” Surely Sans didn’t intend to end their session so quickly, but Papyrus’ warning went unheeded. In fact Sans actually starting pumping the pocket pussy up and down- once, twice, and when Sans stroked downwards the third time, Papyrus came, spurting thick, sticky strands of cum into his brother’s little blue cunt.  _Poor Sans_ , he thought. The smaller skeleton had gotten overly excited and forgotten to pace himself. Sans hadn’t even orgasmed.

“I’m sorry I finished before you, Sa-” but Papy never finished his sentence because Sans started rubbing the swollen lips of the pocket pussy over his still throbbing, still hard member. The tall skeleton moaned as cum and his brother’s juices dribbled out of the gaping hole in the toy onto his sensitive cock. The intense pleasure bordered on pain as Sans rutted him on the dripping wet opening that veritably begged for a more thorough fucking.

The pressure building within Papyrus just from the frottage was unbearable. His bones and dick burned with hyper sensitivity from the previous orgasm, and Sans didn’t let up, increasing the speed and power of his movements. It didn’t take his lazy brother long to reach his second orgasm.

“Sans,” gasped Papyrus, breathing heavily as he laid limp and exhausted on the floor, waves of pleasure still shuddering up and down his spine. “I learned my lesson. I-”

“Sorry, Papyrus, but I think you still have a few orgasms left in you.” Sans caressed his brother’s face affectionately before lowering his hand to brush his fingers over Papyrus’ secret erogenous zone- the very tip of his coccyx.

The sustained erection became painful, but the pure satisfaction of Sans jerking him to full release over and over overcame the discomfort. Sans forced his aching cock into the toy again and began pumping at a furious pace. As the squelching cock sleeve slid up and down his length, Sans twisted it maddeningly. Papyrus almost fainted when he came a third time.

Sans lifted Papyrus into his arms, leaning the larger skeleton against his chest. He massaged the back of his brother’s ribcage lightly. “No napping, Papy,” he murmured close to his brother’s skull. “We’re not done yet.” With those ominous words, Sans began pumping the portable cunt up and down, fast and hard, all over again.

* * *

Papyrus trembled, sweat dripping from his shaking femurs as Sans set a punishing pace. Their mingled fluids oozed onto the floor in a viscous puddle, and his orange tongue lolled as he panted with exertion. Papyrus could only babble incomprehensibly as Sans ruthlessly stroked and squeezed him, bringing him to the edge of the latest in what seemed like an unending string of fruitless orgasms. Papyrus’ fingers were wrapped weakly in the fabric of Sans’ shirt and bandanna as he clung to his brother, trying to stay conscious and upright.  Tears welled in his sockets as he nuzzled into Sans’ neck. Drawing this last orgasm out of him was proving to be torturous. He felt raw; every nerve in his body blazed with overstimulation.

“Ahh… hnnnn,” Papy whimpered at the slow, agonizing approach to his final empty release.

“Wow… That’s it, Papy…” Sans watched his brother come completely undone, and he congratulated himself on a punishment well administered. Now he could finally focus on the aching pressure in his own body. So much of the sticky puddle on the floor resulted from his own arousal, but he’d fought down the sweet release to make sure Papy wouldn’t be so foolish and negligent again.

“Oh my god,” Papyrus cried as he bucked his hips weakly.

“You’re doing so well…” Sans supported his brother’s shaking body with one strong arm as a bone-rattling orgasm ripped through him.

“Sans!! Aaaah…!” Papyrus slumped against him, fully spent and Sans stopped fighting his own orgasm, letting that all encompassing bliss envelope him. He’d resisted for so long. The surrender felt so good.

He shivered as the orgasm ripped through his bones and through the detachable toy he’d made from his magic. He was squirting. He could see it, feel it, and he couldn’t stop it. It lasted forever, and the afterglow? He couldn’t even describe it.

Sans held his brother tightly for awhile as they came down from the exquisite high of deeply fulfilling sex; Papyrus appeared to have dozed off already(so lazy!). Eventually, the ache from the day’s activities surfaced, and Sans decided that movement was the solution to bone-deep weariness and soreness. 

Lifting his brother, he settled Papyrus onto the couch to resume his usual favorite activity- binge napping. He picked up the toy off of the living room floor and took it into the kitchen to wash it. Once he’d cleaned it to his own high standards, he peeked furtively into the living room through the kitchen door.

Papyrus let out a loud snore.

Perfect.

Sans opened the cupboard under the sink and tucked the pocket pussy into the furthest shadowy reaches of the space, piling up the kibble bag and bone attacks around it. Now all he had to do was wait and see if Papyrus would actually miss it this time. Maybe his lazy brother had learned his lesson for once, but Sans doubted it.

Papyrus cracked open one drowsy socket and watched his brother scurrying secretively around in the kitchen.  _Probably hiding the sex toy again_ , he thought. He wondered how long it would take this time before Sans got tired of waiting for him to act and “found it” again.


End file.
